Field of the Invention
The present invention relates to a method and a magnetic resonance system, in order to perform fat saturation when acquiring MR data.
Description of the Prior Art
Several methods for fat saturation are known, including a method that operates with a so-called SPAIR pulse. The SPAIR pulse (“Spectrally Adiabatic Inversion Recovery”) is a frequency-selective adiabatic inversion pulse that is emitted in order to invert only spins of the fat tissue. The actual RF excitation pulse is emitted a particular time period TI after the SPAIR pulse. Conventionally the time period TI is selected such that the longitudinal magnetization of the spins of the fat tissue has as little effect as possible when the MR data is acquired.
When the MR data are acquired in slices, significantly poorer fat saturation may occur as a function of particular measurement parameters in the case of a slice acquired first in time compared to the slices acquired subsequently in time. This different fat saturation then disadvantageously results in an inhomogeneous and disruptive intensity distribution of the fat signal within the reconstructed MR images.
An object of the present invention is to achieve fat saturation which is as homogeneous as possible when MR data is acquired in slices.